Nearly everyone at one time or another has experienced the inconvenience and frustration of having the plug of an electrical appliance become disengaged or uncoupled from an electrical wall outlet or the female end of an extension cord. This often occurs while attempting to operate a hand-manipulated appliance. For example, housewives operating a vacuum cleaner often experience the plug at the end of the vacuum cleaner cord becoming disengaged from a cooperating receptacle of an extension cord or from the wall outlet. As another example, carpenters operating drills and/or circular saws at a construction job site often experience this same difficulty. This can be particularly disruptive to the effective completion of work in this situation where long extension cords are often utilized and the individual may have to, for example, climb down a ladder, walk a significant distance to reengage the plug in the receptacle and then climb back up the ladder to return to the work area.
In many situations, carpenters and other individuals have resorted to tying the adjacent ends of electrical cords together to prevent disengagement of the cooperating plug and receptacle. While this procedure does prevent disengagement, it is not a very effective solution to the problem for a number of reasons. First, it is a relatively time consuming procedure. Second, repeated tying of a cord places a significant strain upon the electrical conductors in the cord. Over time the conductors may be damaged to an extent that at the very least renders the cord useless and in certain situations could potentially lead to a dangerous direct short. Third, it should also be appreciated that it is not possible to tie an electrical cord to a flush mounted wall outlet. Accordingly, this approach cannot be used in this instance to avoid disconnection. Fourth, this procedure does nothing to improve the electrical connection between the male and female connectors.
Recognizing these and other problems, various devices have been developed for maintaining electrical plugs and receptacles in a connected condition. For example, U.S. Pat. No. 4,784,612 to Ryan discloses a hollow capsule including cooperating male and female sections. The electrical plug and receptacle are engaged and placed in the cooperating sections. Next, the sections are threaded together to tightly press the plug and receptacle together. While this device is effective in holding a plug and receptacle of two cords together, it must be appreciated that the device is relatively cumbersome and time consuming to utilize. The device is also not capable of functioning to hold a plug in a flush mounted wall outlet. Additionally, the device does not effectively improve the electrical contact between the connectors.
Another locking electrical connector is disclosed in U.S. Pat. No. 4,627,681 to Hong. More particularly, the female contacts of the Hong patent each include a pair of moveable legs that may be wedged to press against the prongs or blades of a cooperating plug and lock the two in a coupled position. While this device is effective in retaining a plug and receptacle together as well in improving the electrical contact between the connectors, it also suffers from a number of disadvantages.
More particularly, the device does not include a locking plug or male connector. Accordingly, the device is not in any way effective in retaining a male connector in a standard wall outlet of the nonlocking type such as provided under the National Electrical Code as published by the National Fire Protection Association and as outlined in the standards of the National Electrical Manufacturers Association (NEMA) or the American National Standards Institute (ANSI). Stated another way, the male connector disclosed in Hong is only capable of locking with a wall outlet constructed in accordance with the teachings of Hong. Thus, the device disclosed in the Hong patent is of limited value and completely incapable of providing locking action when used with standard, general service nonlocking electrical outlets.
A need is therefore clearly identified for an improved electrical connector adapted to provide the desired locking function.